Aerosol generating device with piercing assembly

ABSTRACT

An electrically heated aerosol-generating device includes a main housing having a cavity, a closure body engageable with the main housing to enclose a cartridge in the cavity, and a heater assembly. The heater assembly includes an elongate piercing assembly configured to extend into the open-ended passage of the cartridge and one or more electric heaters. The piercing assembly has a first hollow shaft portion connected to the main housing and a second hollow shaft portion connected to the closure body. The first and second hollow shaft portions have first and second piercing surfaces configured to breakthrough first and second frangible seals when the cartridge is enclosed in the cavity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/607,977, filed May 30, 2017, which is a continuation of and claimspriority to, international application no. PCT/EP2017/062720, filed onMay 25, 2017, and further claims priority under 35 U.S.C. § 119 toEuropean Patent Application No. 16172186.5, filed May 31, 2016, theentire contents of each of which are incorporated herein by reference.

BACKGROUND Field

Example embodiments relate to an aerosol-generating device for use witha consumable cartridge. At least one example embodiment relates to anelectrically heated aerosol-generating device for use with a consumablecartridge having an internal passage and containing an aerosol-formingsubstrate. At least one example embodiment relates to consumablecartridges for use with aerosol-generating devices, to electricallyheated aerosol-generating systems comprising an electrically heatedaerosol-generating device and a consumable cartridge, and to kits for anelectrically heated aerosol-generating system comprising an electricallyheated aerosol-generating device and a plurality of consumablecartridges.

Description of Related Art

Electrically heated smoking systems may be handheld and may operate byheating an aerosol-forming substrate in an aerosol-generating article,or cartridge. WO2009/132793 describes an electrically heated smokingsystem comprising a shell and a replaceable mouthpiece,the entirecontent of which is incorporated herein by reference thereof.

SUMMARY

At least one example embodiment relates to an electrically heatedaerosol-generating device for use with a consumable cartridge comprisinga storage portion containing an aerosol-forming substrate. The storageportion has a fluid permeable internal surface surrounding an open endedpassage extending through the cartridge. The device comprises a mainhousing having a cavity for receiving a cartridge, a closure bodyengageable with the main housing to enclose the cartridge in the cavity,and a heater assembly for heating the cartridge. The heater assemblyincludes an elongate piercing assembly configured to extend into theopen-ended passage of the cartridge and defining an internal airflowpassage forming part of an airflow pathway through the device. Theelongate piercing assembly includes a first hollow shaft portionconnected to the main housing. The first hollow shaft portion has afirst piercing surface at a distal end thereof. The first piercingsurface is configured to break through a first frangible seal across afirst end of the open ended passage when the cartridge is inserted intothe cavity. The elongate piercing assembly also includes a second hollowshaft portion connected to the closure body. The second hollow shaftportion has a second piercing surface at a distal end thereof. Thesecond piercing surface is configured to break through a secondfrangible seal across a second end of the open ended passage when theclosure body is engaged with the main housing. The first and secondhollow shaft portions extend along a same longitudinal axis when theclosure body is engaged with the main housing. The first and secondhollow shaft portions are sized to meet at a junction such that theelongate piercing assembly extends along an entire length of the cavitywhen the closure body is engaged with the main housing. The heaterassembly also includes at least one electric heater fixed to theelongate piercing assembly. The at least one electric heater has atleast one heating element configured to heat the aerosol formingsubstrate when the cartridge is enclosed in the cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further described, by way of example only, withreference to the accompanying drawings.

FIG. 1 illustrates a longitudinal cross-section of an aerosol-generatingsystem according to a first embodiment;

FIG. 2 illustrates a longitudinal cross-section of a consumablecartridge for use with the aerosol-generating system of FIG. 1 accordingto at least one example embodiment.

FIG. 3A illustrates a longitudinal cross-section of a heater assemblyfor the aerosol-generating system of FIG. 1 according to at least oneexample embodiment.

FIG. 3B illustrates a distal end view of the heater assembly of FIG. 3Aaccording to at least one example embodiment.

FIG. 3C illustrates a side view of the heater assembly of FIG. 3Aaccording to at least one example embodiment.

FIG. 4A illustrates a side view of an electric heater for the heaterassembly of the aerosol-generating system of FIG. 1 according to atleast one example embodiment.

FIG. 4B illustrates an end view of the electric heater of FIG. 4Aaccording to at least one example embodiment.

FIG. 4C illustrates a side view of an electric contact of the electricheater of FIG. 4A, with the other components of the electric heaterremoved for clarity according to at least one example embodiment.

FIGS. 5A to 5C illustrate a method of inserting a consumable cartridgeinto the aerosol-generating device of the aerosol-generating system ofFIG. 1 according to at least one example embodiment.

FIG. 5D illustrates a longitudinal cross-section of the cartridge andheater assembly of the system of FIGS. 5A to 5C in which the system isheld in a tilted position according to at least one example embodiment.

FIG. 6A illustrates a longitudinal cross-section of a second embodimentof heater assembly for the aerosol-generating system of FIG. 1 accordingto at least one example embodiment.

FIG. 6B illustrates a distal end view of the heater assembly of FIG. 6A,in the direction of arrow B in FIG. 6A according to at least one exampleembodiment.

FIG. 6C illustrates a side view of the heater assembly of FIG. 6Aaccording to at least one example embodiment.

FIG. 7A illustrates a longitudinal cross-section of a heater assemblyfor the aerosol-generating system of FIG. 1 according to at least oneexample embodiment.

FIG. 7B illustrates a distal end view of the heater assembly of FIG. 7Aaccording to at least one example embodiment.

FIG. 8 illustrates a side view of a fourth embodiment of heater assemblyfor the aerosol-generating system of FIG. 1 according to at least oneexample embodiment.

DETAILED DESCRIPTION

Example embodiments will become more readily understood by reference tothe following detailed description of the accompanying drawings. Exampleembodiments may, however, be embodied in many different forms and shouldnot be construed as being limited to the example embodiments set forthherein. Rather, these example embodiments are provided so that thisdisclosure will be thorough and complete. Like reference numerals referto like elements throughout the specification.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a”, “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “comprises,” “comprising,”“includes,” and/or “including,” when used in this specification, specifythe presence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on”, “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, components, regions, layersand/or sections, these elements, components, regions, layers and/orsections should not be limited by these terms. These terms are only usedto distinguish one element, component, region, layer or section fromanother region, layer or section. Thus, a first element, component,region, layer or section discussed below could be termed a secondelement, component, region, layer or section without departing from theteachings set forth herein.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper”, and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the example term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

Example embodiments are described herein with reference to cross-sectionillustrations that are schematic illustrations of idealized embodiments(and intermediate structures). As such, variations from the shapes ofthe illustrations as a result, for example, of manufacturing techniquesand/or tolerances, are to be expected. Thus, these example embodimentsshould not be construed as limited to the particular shapes of regionsillustrated herein, but are to include deviations in shapes that result,for example, from manufacturing. For example, an implanted regionillustrated as a rectangle will, typically, have rounded or curvedfeatures and/or a gradient of implant concentration at its edges ratherthan a binary change from implanted to non-implanted region. Likewise, aburied region formed by implantation may result in some implantation inthe region between the buried region and the surface through which theimplantation takes place. Thus, the regions illustrated in the figuresare schematic in nature and their shapes are not intended to illustratethe actual shape of a region of a device and are not intended to limitthe scope of this disclosure.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art. It will be further understood that terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and this specification and will not beinterpreted in an idealized or overly formal sense unless expressly sodefined herein.

Unless specifically stated otherwise, or as is apparent from thediscussion, terms such as “processing” or “computing” or “calculating”or “determining” or “displaying” or the like, refer to the action andprocesses of a computer system, or similar electronic computing device,that manipulates and transforms data represented as physical, electronicquantities within the computer system's registers and memories intoother data similarly represented as physical quantities within thecomputer system memories or registers or other such information storage,transmission or display devices.

In the following description, illustrative embodiments may be describedwith reference to acts and symbolic representations of operations (e.g.,in the form of flow charts, flow diagrams, data flow diagrams, structurediagrams, block diagrams, etc.) that may be implemented as programmodules or functional processes including routines, programs, objects,components, data structures, etc., that perform particular tasks orimplement particular abstract data types. The operations be implementedusing existing hardware in existing electronic systems, such as one ormore microprocessors, Central Processing Units (CPUs), digital signalprocessors (DSPs), application-specific-integrated-circuits (ASICs),SoCs, field programmable gate arrays (FPGAs), computers, or the like.

Further, one or more example embodiments may be (or include) hardware,firmware, hardware executing software, or any combination thereof. Suchhardware may include one or more microprocessors, CPUs, SoCs, DSPs,ASICs, FPGAs, computers, or the like, configured as special purposemachines to perform the functions described herein as well as any otherwell-known functions of these elements. In at least some cases, CPUs,SoCs, DSPs, ASICs and FPGAs may generally be referred to as processingcircuits, processors and/or microprocessors.

Although processes may be described with regard to sequentialoperations, many of the operations may be performed in parallel,concurrently or simultaneously. In addition, the order of the operationsmay be re-arranged. A process may be terminated when its operations arecompleted, but may also have additional steps not included in thefigure. A process may correspond to a method, function, procedure,subroutine, subprogram, etc. When a process corresponds to a function,its termination may correspond to a return of the function to thecalling function or the main function.

As disclosed herein, the term “storage medium”, “computer readablestorage medium” or “non-transitory computer readable storage medium,”may represent one or more devices for storing data, including read onlymemory (ROM), random access memory (RAM), magnetic RAM, core memory,magnetic disk storage mediums, optical storage mediums, flash memorydevices and/or other tangible machine readable mediums for storinginformation. The term “computer-readable medium” may include, but is notlimited to, portable or fixed storage devices, optical storage devices,and various other mediums capable of storing, containing or carryinginstruction(s) and/or data.

Furthermore, at least some portions of example embodiments may beimplemented by hardware, software, firmware, middleware, microcode,hardware description languages, or any combination thereof. Whenimplemented in software, firmware, middleware or microcode, the programcode or code segments to perform the necessary tasks may be stored in amachine or computer readable medium such as a computer readable storagemedium. When implemented in software, processor(s), processingcircuit(s), or processing unit(s) may be programmed to perform thenecessary tasks, thereby being transformed into special purposeprocessor(s) or computer(s).

A code segment may represent a procedure, function, subprogram, program,routine, subroutine, module, software package, class, or any combinationof instructions, data structures or program statements. A code segmentmay be coupled to another code segment or a hardware circuit by passingand/or receiving information, data, arguments, parameters or memorycontents. Information, arguments, parameters, data, etc. may be passed,forwarded, or transmitted via any suitable means including memorysharing, message passing, token passing, network transmission, etc.

According to at least one example embodiment, there is provided anelectrically heated aerosol-generating device for use with a consumablecartridge comprising a storage portion containing an aerosol-formingsubstrate, the storage portion having a fluid permeable internal surfacesurrounding an open ended passage extending through the cartridge. Thedevice comprises a main housing having a cavity for receiving aconsumable cartridge; a closure body engageable with the main housing toenclose the cartridge in the cavity; and a heater assembly for heatingthe cartridge. The heater assembly comprises: an elongate piercingassembly arranged to extend into the open-ended passage of the cartridgeand defining an internal airflow passage forming part of an airflowpathway through the device; and one or more electric heaters fixed tothe elongate piercing assembly. The one or more electric heaters eachhave at least one heating element for heating the aerosol formingsubstrate when the cartridge is enclosed in the cavity. The elongatepiercing assembly comprises a first hollow shaft portion connected tothe main housing and has a first piercing surface at its distal end forbreaking through a first frangible seal across a first end of the openended passage when the cartridge is inserted into the cavity. Theelongate piercing assembly also comprises a second hollow shaft portionconnected to the closure body and has a second piercing surface at itsdistal end for breaking through a second frangible seal across a secondend of the open ended passage when the closure body is engaged with themain housing. The first and second hollow shaft portions are arranged toextend along the same longitudinal axis when the closure body is engagedwith the main housing. The first and second hollow shaft portions aresized to meet at a junction such that the elongate piercing assemblyextends along the entire length of the cavity when the closure body isengaged with the main housing.

In at least one example embodiment, having a two-part piercing assemblymay allow the seals at either ends of a cartridge to be more easilybroken. By breaking the seals inwardly, the seals may be substantiallyprevented from moving away from the hollow shaft portions and thestresses exerted by the first and second piercing surfaces on the sealsare higher, causing the seals to break more easily. Additionally, byconnecting one of the hollow shaft portions to the closure body, it maybe possible to substantially prevent the seal at the downstream end ofthe cartridge from being broken until the closure body is placed overthe main housing. This may reduce the risk of liquid leakage duringinsertion of the cartridge. Further, by providing the electric heatersas part of the device, cartridges for use with the device may besimplified, less expensive and more robust than cartridges which includean electric heater. Accordingly, reducing the cost of cartridges, evenif it requires a more expensive device, can lead to significant costsavings for both manufacturers and consumers.

The heater assembly comprises an elongate piercing assembly to which oneor more electric heaters is fixed. Thus, the elongate piercing assemblydoubles as a mount for the one or more electric heaters and as apiercing member. This may allow the elongate piercing assembly to piercethe seal at the end of a cartridge conveniently and easily duringinsertion of the cartridge into the device. To facilitate piercing ofthe seal, the distal ends of the first and second hollow shaft portionsat which the first and second piercing surfaces are located have across-sectional area that is smaller than the cross-sectional area ofthe region of the hollow shaft member immediately proximal of thepiercing surface. In at least one example embodiment, thecross-sectional areas of the first and second hollow shaft portionsnarrow towards a tapered tip at their respective distal ends. Thecross-sectional areas of the first and second hollow shaft portions maynarrow towards a point at their respective distal ends.

The elongate piercing assembly has an internal airflow passage formingpart of an airflow pathway through the device. With this arrangement,the elongate piercing assembly may provide a support for the electricheaters as well as providing an airflow channel. This may allow for adevice which is compact and may facilitate cost-effective high volumemanufacturing. Having an airflow passage within the first and secondhollow shaft portions may help to substantially minimise and/or reduceheat loss from the device and may allow the housing of the device to beeasily maintained at a temperature which is comfortable to hold.Furthermore, vaporised aerosol-forming substrate in the air flow throughthe hollow shaft portions can begin to cool within the airflow passageto form an aerosol, allowing the overall length of the device to bereduced.

The frangible seals form barriers across the ends of the cartridge priorto insertion into the cavity of the device. The frangible seals may bemade from any suitable material or materials, for example from a film,such as a metal film. In at least one example embodiment, the frangibleseal may be formed of an aluminium film.

In at least one example embodiment, the first and second hollow shaftportions are arranged to extend along the same longitudinal axis whenthe closure body is engaged with the main housing.

The first and second hollow shaft portions are also sized to meet at ajunction such that the elongate piercing assembly extends along theentire length of the cavity when the closure body is engaged with themain housing.

The distal ends of the first and second hollow shaft portions areco-operatively shaped such that a seal is formed around the junction.With this arrangement, air flow may be substantially confined to theinternal airflow passage through the elongate piercing assembly, ratherthan passing into the storage portion of the cartridge, therebyfacilitating the delivery of a consistent aerosol.

The distal ends of the first and second hollow shaft portions may haveany suitable, co-operative piercing shape. In at least one exampleembodiment, the distal end of one of the first and second hollow shaftportions has an inwardly tapering outer surface and the distal end endof the other one of the first and second hollow shaft portions has anoutwardly tapering inner surface, the inner and outer surfaces beingshaped such that the inwardly tapering outer surface fits within theoutwardly tapering inner surface to form the seal when the closure bodyis engaged with the main housing. This may allow the first and secondhollow shaft portions to be mated easily. In at least one exampleembodiment, the distal end of the first hollow shaft portion may have aninwardly tapering outer surface and the distal end end of the secondhollow shaft portion may have an outwardly tapering inner surface. Theinner and outer surfaces re shaped such that the inwardly tapering outersurface fits within the outwardly tapering inner surface to form theseal when the closure body is engaged with the main housing.

The closure body may function simply as a lid for closing the cavity. Inat least one example embodiment, the closure body forms a mouthpieceportion by which air can be drawn through the airflow pathway of theaerosol generating device. The mouthpiece portion may have an outletthrough which aerosol generated by the device can be drawn. As usedherein, the term “mouthpiece portion” means a portion of the device thatis configured to be drawn upon and through when the aerosol exits thedevice.

The first and second hollow shaft portions are electrically conductive.In at least one example embodiment, the first and second hollow shaftportions may be arranged to connect the one or more electric heaters toan electrical power supply. In at least one example embodiment, thefirst and second hollow shaft portions may be formed from anelectrically conductive material, such as metal. In at least one exampleembodiment, the first and second hollow shaft portions may be formedfrom an electrically insulative substrate, such as a polymer substrate,and may further comprise one or more electrical conductors attached tothe substrate for connecting the electric heaters to an electrical powersource. In at least one example embodiment, the first and second hollowshaft portions may comprise an electrically insulative substrate onwhich electrical conductors are applied for example by deposition,printing, or by laminating with the substrate as a laminated foil. Thelaminate foil may then be shaped or folded to form the first and secondhollow shaft portions.

The heater assembly may comprise a single electric heater comprising atleast one heating element for heating the aerosol-forming substrate of acartridge received in the cavity. In at least one example embodiment,the heater assembly comprises a plurality of electric heaters which arefixed to and spaced along the length of the elongate piercing assembly.

In at least one example embodiment, this arrangement may allow for moreeven heating of the aerosol-forming substrate in the cartridge relativeto devices in which only one electric heater is provided or in which aplurality of electric heaters are provided but which are not spacedalong the length of the elongate piercing assembly. It may also allowthe device to heat parts of a cartridge to which would not be heated bydevices having only a single heater, enabling more of theaerosol-forming substrate in each cartridge to be vaporised, reducingwaste. Additionally, when used with cartridges having a plurality ofdifferent aerosol-forming substrates stored separately, the plurality oflongitudinally spaced apart electric heaters allow separate heating ofthe different aerosol-forming substrates to produce an aerosol withparticularly desirable characteristics.

Where the heater assembly comprises a plurality of electric heaters, allof the electric heaters may be fixed to one of the first and secondhollow shaft portions. In at least one example embodiment, the pluralityof electric heaters comprises one or more electric heaters fixed to thefirst hollow shaft portion and one or more electric heaters fixed to thesecond hollow shaft portion. The plurality of electric heaters may beevenly or unevenly divided between the first and second hollow shaftportions. In at least one example embodiment, one of the first andsecond hollow shaft portions may comprise a single electric heater, withthe remaining electric heaters being fixed to the other of the first andsecond hollow shaft portions.

One or more electric heaters may extend across the airflow passagetransverse to the longitudinal axis of the elongate piercing assembly.In at least one example embodiment, the one or more electric heaters mayspan the airflow passage. In at least one example embodiment, this mayplace the electric heater directly in the path of being drawn throughthe device when in use. This may allow vaporised aerosol-formingsubstrate to be more readily entrained into air flowing through thedevice to form an aerosol. It may also allow the electric heater to becooled by the air flowing through the device, reducing the risk ofoverheating. By extending across the airflow passage, the electricheaters may help to mix the vaporise aerosol-forming substrate with theair flow through the hollow shaft portion, for example by creatingturbulence in the air flow. This may result in a more homogenous aerosolwhen compared to examples in which no electric heaters extend across theairflow passage.

Where the heater assembly comprises a plurality of electric heaters, theplurality of electric heaters may each extend across the internalairflow passage transverse to the longitudinal direction of the elongatepiercing assembly. In at least one example embodiment, the plurality ofelectric heaters may each span the airflow passage.

Where one or more of the electric heaters extend across the airflowpassage, the longitudinal axis of one or more of the electric heatersmay be perpendicular to the longitudinal axis of the hollow shaftportion. One or more of the electric heaters extending across theairflow passage may be arranged such that its longitudinal axis isoblique to the longitudinal axis of the hollow shaft portion.

Where the plurality of electric heaters extend across the airflowpassage transverse to the longitudinal axis of the hollow shaft portion,one or more of the plurality of electric heaters may extend across theairflow passage such that its longitudinal axis is rotated about thelongitudinal axis of the elongate piercing assembly relative to thelongitudinal axis of at least one other of the electric heaters. Thatis, when longitudinal axes of the electric heaters are projected onto aplane extending perpendicularly to the longitudinal axis of the elongatepiercing assembly, the longitudinal axis of one or more of the pluralityof electric heaters extends across the airflow passage at an angle tothe longitudinal axis of at least one other of the electric heaters.With this arrangement, the electric heaters may more readily interceptair flowing through the device relative to arrangements in which theelectric heaters are aligned about the longitudinal axis of the elongatepiercing assembly. It also means that at least one of the electricheaters may be in fluid communication with the storage portion of acartridge at a position which is offset around the circumference of theelongate piercing assembly from one or more of the remaining electricheaters. This may allow the device to more uniformly consumeaerosol-forming substrate stored in a cartridge, reducing waste,relative to arrangements in which the electric heaters are aligned aboutthe longitudinal axis of the hollow shaft portion. Additionally, in theevent that liquid aerosol-forming substrate leaks from one of theelectric heaters during use, by having one or more of the electricheaters extending at a different angle, the liquid may be more readilyintercepted and absorbed into one of the adjacent electric heaters andmay thus reduce liquid leakage from the device.

In at least one example embodiment, one or both of the first and secondhollow shaft portions comprises a plurality of apertures in which theplurality of electric heaters are held, the plurality of electricheaters being in fluid communication with the storage portion of acartridge received in the cavity through the plurality of apertures.

The apertures may be formed in the first or second hollow shaft portionafter the respective hollow shaft portion has been formed, for exampleby punching, drilling, milling, erosion, electro erosion, cutting, orlaser cutting. The apertures may be formed integrally with the first orsecond hollow shaft portion at the time of forming the hollow shaftportion, for example by casting or moulding the hollow shaft portionwith the apertures or by a deposition process, such aselectrodeposition.

As used herein, the term “aerosol-generating device” refers to a devicethat interacts with an aerosol-generating article, such as a consumablecartridge, to generate an aerosol.

In at least one example embodiment, the aerosol-generating device isportable. The aerosol-generating device may have a size comparable to aconventional cigar or cigarette. The aerosol-generating device may havea total length ranging from about 30 mm to about 150 mm. Theaerosol-generating device may have an external diameter ranging fromabout 5 mm to about 30 mm.

The heater assembly may be fixed to, or integral with, the main housingand the closure body of the device. In at least one example embodiment,the heater assembly may be removably fastened to one or both of the mainhousing and the closure body. This may allow the heater assembly to beat least partially removed from the device, for example for maintenanceor cleaning or to enable replacement of the heater assembly. The heaterassembly may be removable coupled to the main housing or the closurebody by one or more electrical and mechanical connection means.

The heater assembly comprises one or more electric heaters. In at leastone example embodiment, the heater assembly may comprise one, two,three, four, five, six or more electric heaters fixed to the elongatepiercing assembly. Where the heater assembly comprises one or moreelectric heaters, the electric heaters may be spaced along the length ofthe elongate piercing assembly. Each electric heater comprises at leastone heating element. Each electric heater may comprise more than oneheating element, for example two, or three, or four, or five, or six ormore heating elements. The heating element or heating elements may bearranged appropriately so as to most effectively heat theaerosol-forming substrate of a cartridge inserted into the cavity of themain housing.

Each heating element may be a coil of electrically resistive wire. Theheating element may be formed by stamping or etching a sheet blank thatcan be subsequently wrapped around a wick. In at least one exampleembodiment, the heating element is a coil of electrically resistivewire. The pitch of the coil is ranges from about 0.5 mm to about 1.5 mm.In at least one example embodiment the pitch of the coil is about 1.5mm. The pitch of the coil means the spacing between adjacent turns ofthe coil. The coil may comprise fewer than six turns, and may have fewerthan five turns. The electrically resistive wire has a diameter rangingfrom about 0.10 mm to about 0.15 mm. In at least one example embodiment,the electrically resistive wire has a diameter of about 0.125 mm. Theelectrically resistive wire is formed of 904 or 301 stainless steel.Examples of other suitable metals include titanium, zirconium, tantalumand metals from the platinum group. Examples of other suitable metalalloys include, Constantan, nickel-, cobalt-, chromium-,aluminium-titanium-zirconium-, hafnium-, niobium-, molybdenum-,tantalum-, tungsten-, tin-, gallium-, manganese- and iron-containingalloys, and super-alloys based on nickel, iron, cobalt, stainless steel,Timetal®, iron-aluminium based alloys and iron-manganese-aluminium basedalloys. Timetal® is a registered trade mark of Titanium MetalsCorporation, 1999 Broadway Suite 4300, Denver, Colo. In compositematerials, the electrically resistive material may optionally beembedded in, encapsulated or coated with an insulating material orvice-versa, depending on the kinetics of energy transfer and theexternal physicochemical properties required. The heating element maycomprise a metallic etched foil insulated between two layers of an inertmaterial. In that case, the inert material may comprise Kapton®,all-polyimide or mica foil. Kapton® is a registered trade mark of E.I.du Pont de Nemours and Company, 1007 Market Street, Wilmington, Del.19898, United States of America. The heating element may also comprise ametal foil, e.g., an aluminium foil, which is provided in the form of aribbon.

The at least one heating element may operate by resistive heating. Inother words the material and dimensions of the heating element may bechosen so that when a particular current is passed through the heatingelement the temperature of the heating element is raised to a desired(or, alternatively predetermined) temperature. The current through theheating element may be applied by conduction from a battery or may beinduced in the heating element by the application of a variable magneticfield around the heating element.

The at least one heating element may comprise an inductive heatingelement, such that, where the device forms part of an aerosol-generatingsystem consisting of the aerosol generating device and a removableaerosol-generating article, no electrical contacts are formed betweenthe article and the device. The device may comprise an inductor coil anda power supply configured to provide high frequency oscillating currentto the inductor coil. The article may comprise a susceptor elementpositioned to heat the aerosol-forming substrate. As used herein, a highfrequency oscillating current means an oscillating current having afrequency ranging from about 500 kHz to about 10 MHz.

Electric heaters according to at least one example embodiment maycomprise a capillary body. The at least one heating element may bearranged on an outer surface of the capillary body, for example as acoil. The capillary body may comprise any suitable material orcombination of materials which is able to convey a liquidaerosol-forming substrate along its length. The capillary body may beformed from a porous material, but this need not be the case. Thecapillary body may be formed from a material having a fibrous or spongystructure. The capillary body comprises a bundle of capillaries. In atleast one example embodiment, the capillary body may comprise aplurality of fibres or threads or other fine bore tubes. The capillarybody may comprise sponge-like or foam-like material. The structure ofthe capillary body forms a plurality of small bores or tubes, throughwhich an aerosol-forming liquid can be transported by capillary action.The material or materials will depend on the physical properties of theaerosol-forming substrate. Examples of suitable capillary materialsinclude a sponge or foam material, ceramic- or graphite-based materialsin the form of fibres or sintered powders, foamed metal or plasticsmaterial, a fibrous material, for example made of spun or extrudedfibres, such as cellulose acetate, polyester, or bonded polyolefin,polyethylene, terylene or polypropylene fibres, nylon fibres, ceramic,glass fibres, silica glass fibres, carbon fibres, metallic fibres ofmedical grade stainless steel alloys such as austenitic 316 stainlesssteel and martensitic 440 and 420 stainless steels. The capillary bodymay have any suitable capillarity so as to be used with different liquidphysical properties. The liquid has physical properties, including butnot limited to viscosity, surface tension, density, thermalconductivity, boiling point and vapour pressure, which allow the liquidto be transported through the capillary body. The capillary body may beformed from heat-resistant material. In at least one example embodiment,the capillary body may comprise a plurality of fibre strands. Theplurality of fibre strands may be generally aligned along the length ofthe capillary body.

Electric heaters according to at least one example embodiment maycomprise a capillary body; a heating element arranged on an outersurface of the capillary body; and a pair of spaced apart electricalcontacts fixed around the capillary body and over the heating elementfor electrically coupling the electric heater to the elongate supportmember. By fixing the electrical contacts around the capillary body andover the heating element, the electrical contacts may secure the heatingelement to the outer surface of the capillary body as well as providingan electrical connection. In at least one example embodiment, this mayrequire fewer manufacturing steps than existing systems in which theends of the heater element are manually connected to the electricalcontacts, for example by welding. It may also allow the electric heaterto be manufactured on an automated assembly line, so such devices can bemanufactured more quickly with high repeatability. In such embodiments,at least one of the electrical contacts is dimensioned such that thereis a frictional fit between an inner surface of that electrical contactand the outer surface of the capillary body. Providing such a frictionalfit may allow the electrical contact to be secured on the capillary bodywithout the need for additional fastening means or fastening steps. Inat least one example embodiment, each electrical contact is dimensionedsuch that there is a frictional fit between the inner surface of theelectrical contact and the outer surface of the capillary body. Theheating element may comprise a coil of electrically resistive wire woundaround the capillary body, for example along the entire length of thecapillary body.

Where electric heaters comprise a capillary body, a heating elementarranged on an outer surface of the capillary body, and a pair of spacedapart electrical contacts fixed around the capillary body and over theheating element, the capillary body is compressible and the electricalcontacts extend around the circumference of the capillary body such thatthere is an interference fit between the electrical contacts and thecapillary body. This may help to ensure that the heating element issecurely fixed to the capillary body by the electrical contact withoutthe need for adhesive or additional fixation steps, such as soldering orwelding. It may also help to ensure a reliable electrical connectionbetween the electrical contact and the heating element. The electricalcontacts extend around more than about 50 percent of the circumferenceof the capillary body. This may result in a more secure fixation of theelectrical contacts to the capillary body relative to examples in whichthe electrical contacts extend around less than 50 percent of thecircumference of the capillary body. It may also help to ensure areliable electrical connection between the electrical contact and theheating element.

Where electric heaters comprise a capillary body, a heating elementarranged on an outer surface of the capillary body, and a pair of spacedapart electrical contacts fixed around the capillary body and over theheating element, one or both of the electrical contacts may extendaround substantially the entire circumference of the capillary body. Atleast one of the electrical contacts may circumscribe the capillarybody. In such example embodiments, the electrical contact may be ringshaped. In at least one example embodiment, both electrical contactscircumscribe the capillary body. This may result in a more securefixation of the electrical contacts to the capillary body relative toexamples in which the electrical contacts extend around less than theentire circumference of the capillary body. It may also help to ensure areliable electrical connection between the electrical contact and theheating element irrespective of the specific arrangement of the heatingelement on the outer surface of the capillary body and withoutrestricting the arrangement of the heating element to ensure contactbetween the electrical contacts and the heating element. In certainembodiments, both electrical contacts circumscribe the capillary bodyand are dimensioned such that there is an interference fit between theelectrical contacts and the capillary body.

Where electric heaters comprise a capillary body, a heating element, anda pair of spaced apart electrical contacts fixed around the capillarybody and over the heating element, the electrical contacts may be rigid.This may result in a more robust assembly than one in which theelectrical contacts are flexible. The electrical contacts may eachcomprise a ring of rigid material, such as a metallic ring. This mayprovide an electrical contact with high mechanical resistance andreliable electrical connection to the heating element. It may alsoenable the electric heater to be connected to the heater assembly bysnap fitting the electrical contacts into a retaining clip in thedevice. Where the electrical contacts extend around the circumference ofthe capillary body, the opposed ends of each electrical contact may beco-operatively shaped such that the joint is non-linear or extends alongan oblique line. In this context, the term “oblique line” means that thejoint extends along a line which is nonparallel to the longitudinal axisof the capillary body. By having a joint which is non-linear orextending along an oblique line, relative movement between the opposedends of each electrical contact in the longitudinal direction of thecapillary body can be substantially prevented and/or reduced.

Where electric heaters comprise a capillary body, a heating element, anda pair of spaced apart electrical contacts fixed around the capillarybody and over the heating element, the capillary body may be anysuitable shape. In certain embodiments, the capillary body is elongate.The pair of electrical contacts may be spaced apart in a lengthdirection of the capillary body. For example, the pair of electricalcontacts may comprise a first electrical contact at or adjacent to afirst end of the capillary body and a second electrical contact at anyother location, such as at a midpoint along the length of the capillarybody. The pair of electrical contacts may comprise a first electricalcontact at or adjacent to a first end of the capillary body and a secondelectrical contact at or adjacent to the second end of the capillarybody.

Where electric heaters comprise a capillary body, the electric heatermay further comprise a rigid support member extending along at leastpart of the length of the capillary body. The rigid support memberincreases the strength and rigidity of the electric heater to ensure arobust assembly which is easy to handling during manufacture. The rigidsupport member may be formed from a single, unitary component or from aplurality of components connected together. The rigid support member mayextend through the core of the capillary body. The support member may besurrounded by the capillary body. The support member may becircumscribed by the capillary body. The presence of the rigid supportmember may reduce the overall radial compressibility of the capillarybody, thus helping to ensure a tight fit between the electrical contactsand the heating element. The support member may be arranged on an outersurface of the capillary body. In some examples, the rigid supportmember comprises a central portion and a plurality of transverse ribs.This cross-sectional shape may result in a support member having asuitable rigidity without occupying a large amount of space within thecapillary body and thus significantly reducing the wicking ability ofthe capillary body. The plurality of transverse ribs may comprise aplurality of radially extending ribs.

In at least one example embodiment, one or both of the first and secondhollow shaft portions may be electrically conductive. The electricallyconductive hollow shaft portion or portions may comprise a plurality ofapertures, wherein the one or more electric heaters may be formed by oneor more narrow regions of the hollow shaft portion between adjacentapertures.

In at least one example embodiment, having a heater assembly with one ormore integral electric heaters may require fewer manufacturing steps andmay allow the heater assembly to be manufactured on an automatedassembly line. This may allow aerosol-generating devices to bemanufactured more quickly, simply and with high repeatability andconsistency. Such devices may be simplified, less expensive and morerobust than devices in which the heater assembly comprises complicatedand potentially fragile connections.

The apertures may be formed in one or both hollow shaft portions afterthe hollow shaft portion has been formed, for example by punching,drilling, milling, erosion, electro erosion, cutting, or laser cutting.The apertures may be formed integrally with the hollow shaft portion atthe time of forming the hollow shaft portion, for example by casting ormoulding the hollow shaft portion with the apertures or by forming thehollow shaft portion with the apertures in a deposition process, such aselectrodeposition.

As used herein, “electrically conductive” means formed from a materialhaving a resistivity of 1×10⁻⁴ Ωm, or less. As used herein,“electrically insulating” means formed from a material having aresistivity of 1×10⁴ Ωm or more.

The at least one electric heater may be arranged on the hollow shaftportion in any suitable manner. In some example embodiments, the atleast one electric heater circumscribes the hollow shaft portion. Thismay allow for more even heating of the aerosol-forming substrate in thecartridge relative to devices in which the at least one electric heaterdoes not circumscribe the hollow shaft portion. The at least oneelectric heater may circumscribe the hollow shaft portion continuously.The at least one electric heater may circumscribe the hollow shaftportion discontinuously in the form of a plurality of electric heatersspaced apart in the circumferential direction of the hollow shaftportion. In other example embodiments, the at least one electric heatermay extend around only part of the circumference of the hollow shaftportion.

Devices according to at least one example embodiment comprise a mainhousing and a closure body. The main housing may be elongate. The mainhousing may comprise any suitable material or combination of materials.Examples of suitable materials include metals, alloys, plastics orcomposite materials containing one or more of those materials, orthermoplastics that are suitable for food or pharmaceuticalapplications, for example polypropylene, polyetheretherketone (PEEK) andpolyethylene. In at least one example embodiment, the material is lightand non-brittle.

In at least one example embodiment, devices may further compriseelectric circuitry connected to the heater assembly and to an electricalpower source. The electric circuitry may comprise a microprocessor,which may be a programmable microprocessor, a microcontroller, or anapplication specific integrated chip (ASIC) or other electroniccircuitry capable of providing control. The electric circuitry maycomprise further electronic components. The electric circuitry may beconfigured to regulate a supply of current to the heater assembly.Current may be supplied to the heater assembly continuously followingactivation of the device or may be supplied intermittently, such as on apuff by puff basis. The electric circuitry may comprise DC/AC inverter,which may comprise a Class-D or Class-E power amplifier.

The device comprises a power supply within the housing. In at least oneexample embodiment, the power supply may be a battery such as a lithiumiron phosphate battery, or another form of charge storage device such asa capacitor. The power supply may require recharging and may have acapacity that allows for the storage of enough energy for one or moresmoking experiences. In at least one example embodiment, the powersupply may have sufficient capacity to allow for the continuousgeneration of aerosol for a period of around six minutes, correspondingto the typical time taken to smoke a cigarette, or for a period that isa multiple of six minutes. In at least one example embodiment, the powersupply may have sufficient capacity to allow for a desired (or,alternatively predetermined) number of puffs or discrete activations.

The device may comprises power supply connected to the heater assemblyand electric circuitry connected to the power supply and to the heaterassembly.

Where the heater assembly comprises a plurality of electric heaterswhich are fixed to and spaced along the length of the elongate piercingassembly, the electric circuitry is configured to measure one or moreelectrical parameters of the plurality of electric heaters and tocalculate an estimated remaining amount of aerosol forming substrate inthe cartridge or an estimated distribution of aerosol forming substratein the cartridge, based on the measured electrical parameters.

As used herein, the term “electrical parameter” is used to describe anelectrical property, value or attribute that can be quantified bymeasurement, for example, resistivity, conductivity, impedance,capacitance, current, voltage, and resistance.

In at least one example embodiment, with this arrangement, the electricheaters have dual functionality: heating and sensing. This may allow thedevice to determine at any time an estimate of the state of theaerosol-forming substrate remaining in the cartridge. From this, thedevice may be operated differently by the electric circuitry to maintaindesirable aerosol properties, or may indicate the current state of theaerosol-forming substrate to allow an adult vapor to take appropriateaction, such as changing the cartridge or the orientation of the device.

In such example embodiments, the electric circuitry is configured toseparately measure the one or more electrical parameters of each of theplurality of electric heaters and to calculate the estimated remainingamount, or the estimated distribution, or the estimated remaining amountand the estimated distribution, based on differences in the measuredelectric parameters of two or more of the plurality of electric heaters.

Where the device comprises a power supply connected to the heaterassembly and electric circuitry connected to the power supply and to theheater assembly, the device further comprises an indicator connected topower supply. The electric circuitry may be configured to operate theindicator in response to the estimated remaining amount or the estimateddistribution. The indicator may have any suitable configuration, forexample the indicator may be for example a display, an audio output, ahaptic output, or any combination thereof. This may allow the device toconvey information regarding the estimated remaining amount or theestimated distribution, or both, of liquid aerosol-forming substrate inthe cartridge.

The electric circuitry may be configured to operate the indicator whenthe estimated remaining amount falls below a threshold value to alertthe adult vapor and to prompt the adult vapor into replacing thecartridge. The control circuitry may be configured to operate theindicator when the estimated distribution suggests that device has beenheld at a particular angle for too long so that the device may bereoriented, at least temporarily, so that the aerosol-forming substratemay be redistributed in the storage portion.

The control circuitry may be configured to inform an adult vapor aboutthe estimated remaining amount or estimated distribution via acommunication link with a separate device, such as a smartphone,swart-watch, tablet, desktop computer, or similar device.

Where the device comprises electric circuitry connected to a powersource and configured to measure one or more electrical parameters ofthe plurality of electric heaters and to calculate an estimatedremaining amount or estimated distribution, the electric circuitry maybe further configured to control a supply of power to one or more of theplurality of electric heaters separately in response to the estimatedremaining amount or the estimated distribution.

In at least one example embodiment, this may allow the device todetermine which of the electric heaters is in the best condition togenerate aerosol in the most effective way and to vary the supply ofpower accordingly. This may help to substantially minimise and/or reducevariations in aerosol properties caused by variations in thedistribution of the aerosol-forming substrate within the cartridge. Itmay also reduce overall energy consumption of the device by allowing theenergy draw of the electric heaters to be selected in the most effectivemanner. The electric circuitry may be configured to increase the supplyof power to one or more of the plurality of electric heaters in responseto the estimated remaining amount or the estimated distribution.

The electric circuitry may be configured to reduce the supply of powerto one or more of the plurality of electric heaters in response to theestimated remaining amount or the estimated distribution.

In at least one example embodiment, this may allow the energyconsumption of one or more of the electric heaters to be selectivelyreduced, for example where the estimated remaining amount or estimateddistribution indicates that a particular electric heater is not wellplaced to generate an aerosol. It may also reduce the risk of damage tothe electric heaters due to over heating, for example where a liquidaerosol-forming substrate is used and the electrical parameters indicatethat one or more of the electric heaters is dry or partially dry.

The electric circuitry may be configured to reduce or increase thesupply of power to one or more of the plurality of electric heaters inresponse to the estimated remaining amount or the estimateddistribution. The electric circuitry may be configured to reduce thesupply of power to one or more of the plurality of electric heaterswhile simultaneously increasing the supply of power to a different oneor more of the plurality of electric heaters, in response to theestimated remaining amount or the estimated distribution.

At least one example embodiment relates to an electrically heatedaerosol-generating system comprising an electrically heatedaerosol-generating device according to any of the example embodimentsdescribed above, and a consumable cartridge comprising a storage portioncontaining an aerosol forming substrate. The storage portion has a fluidpermeable internal surface surrounding an open-ended passage extendingthrough the cartridge. The cartridge is enclosed in the cavity such thatthe elongate piercing assembly extends into the open-ended passage ofthe cartridge.

The system comprises a consumable cartridge. The consumable cartridgemay be removably coupled to the aerosol-generating device. As usedherein, the term ‘removably coupled’ is used to mean that the cartridgeand device can be coupled and uncoupled from one another withoutsignificantly damaging either the device or cartridge. The cartridge maybe removed from the aerosol-generating device when the aerosol-formingsubstrate has been consumed. The cartridge may be disposable. Thecartridge may be reusable. The cartridge may be refillable withaerosol-forming substrate. The cartridge may be replaceable in theaerosol-generating device.

The aerosol-generating system may comprise an aerosol-forming chamber inwhich aerosol forms from a super saturated vapour and is then carriedthrough the air outlet. An air inlet, the air outlet and the chamber arearranged so as to define an airflow route from the air inlet to the airoutlet via the aerosol-forming chamber, so as to convey the aerosol tothe air outlet. The aerosol-forming chamber may be defined by one orboth of the cartridge and the aerosol-generating device.

As used herein, the term ‘aerosol-forming substrate’ relates to asubstrate capable of releasing volatile compounds that can form anaerosol. Such volatile compounds may be released by heating theaerosol-forming substrate. An aerosol-forming substrate may be part ofan aerosol-generating article, such as a cartridge, or smoking article.

The aerosol-forming substrate is an aerosol-forming liquid. As usedherein, the terms “aerosol-forming liquid” and “liquid aerosol-formingsubstrate” are interchangeable. The storage portion comprises acapillary wick forming part or all of the internal surface fortransporting liquid aerosol-forming substrate from the storage portionto the heater assembly.

The storage portion may contain a single aerosol-forming substrate. Thestorage portion may contain two or more aerosol-forming substratesstored separately. In at least one example embodiment, the storageportion may contain three aerosol-forming substrates stored separately,four aerosol-forming substrates stored separately, five aerosol-formingsubstrates stored separately, or six or more aerosol-forming substratesstored separately. Where the storage portion contains two or moreaerosol-forming substrates stored separately, the heater assemblycomprises a plurality of electric heaters spaced along the length of theelongate piercing assembly, the plurality of electric heaters includingat least one electric heater for each of the aerosol-forming substrates,each of the electric heaters being configured to heat its correspondingaerosol-forming substrate. This allows the aerosol-forming substrates tobe heated independently.

In at least one example embodiment, the storage portion of theconsumable cartridge contains first and second aerosol formingsubstrates stored separately and the heater assembly comprises aplurality of electric heaters spaced along the length of the elongatepiercing assembly. The plurality of electric heaters compress a firstelectric heater configured to heat the first aerosol forming substrateto form a first aerosol and a second electric heater configured to heatthe second aerosol forming substrate to form a second aerosol.

In at least one example embodiment, the storage portion is compressibleand the diameter of the open-ended passage extending through thecartridge is less than the outer diameter of one or both of the firstand second hollow shaft portions. With this arrangement, the storageportion may be radially compressed by the piercing assembly to ensure atight fit between the cartridge and the respective hollow shaft portion.This may facilitate contact between the electric heaters and theaerosol-forming substrate in the storage portion to allow consistentaerosol properties. It may also restrict or eliminate air flow betweenthe cartridge and the outside of the hollow shaft portion, therebyfacilitating the delivery of a consistent aerosol.

At least one example embodiment relates to a consumable cartridge for anelectrically heated aerosol-generating device according to any of theexample embodiments described above. The cartridge comprises a storageportion containing an aerosol-forming substrate, a fluid permeableinternal surface surrounding an open ended passage extending through thecartridge, a first frangible seal across a first end of the open-endedpassage, and a second frangible seal across a second end of theopen-ended passage.

The open-ended passage within the cartridge may allow for a system thatis compact. It may also allow the cartridge to be used in a system whichis symmetrical and balanced which is may be helpful when the system is ahandheld system. An internal passage may also substantially minimiseand/or reduce heat losses from the device and allow the housing of thedevice and cartridge to be easily maintained at a temperature than iscomfortable to hold.

The open-ended passage forms a guiding and aligning means thatco-operates with the elongate piercing assembly of devices to facilitatethe correct orientation and position of the cartridge into the device.

As used herein, the term “fluid permeable surface” refers to a surfacethat allows liquid or gas to permeate through it. The internal surfacemay have a plurality of openings formed in it to allow fluid to permeatethrough it.

The upstream and downstream ends of the cartridge may be capped byfrangible seals. The cartridge may further include a sealing ring at oneor both of the upstream and downstream ends of the open-endedpassageway.

In at least one example embodiment, the aerosol forming substratecomprises a liquid aerosol forming substrate.

The storage portion contains first and second aerosol forming substratesstored separately. The first and second aerosol-forming substrates maybe different.

The cartridge may comprise a first sealed compartment comprising a firstaerosol-forming substrate and a second sealed compartment comprising asecond aerosol-forming substrate. The first compartment and the secondcompartment are arranged in series from the upstream end to thedownstream end of the cartridge. That is, the second compartment isdownstream of the first compartment. In at least one example embodiment,each of the first compartment and the second compartment comprises afrangible barrier at each end. The frangible barrier is configured suchthat the barrier can be pierced by the elongate support member when thecartridge is inserted into the aerosol-generating device. In at leastone example embodiment, each frangible barrier is made from metal film,such as an aluminium film. In at least one example embodiment, the firstcompartment and the second compartment of the cartridge abut oneanother. In at least one example embodiment, the first compartment andthe second compartment may be spaced apart. The volume of the firstcompartment and the second compartment may be the same or different. Inat least one example embodiment, the volume of the second compartment isgreater than the volume of the first compartment.

The storage portion forms an annular space surrounding the internalopen-ended passage. The cartridge may have a generally cylindrical shapeand may have any desired cross-section, such as circular, hexagonal,octagonal or decagonal.

In at least one example embodiment, the storage portion may comprise atubular porous element in which a liquid aerosol-forming substrate isabsorbed.

The storage portion comprises a capillary wick and a capillary materialcontaining liquid aerosol-forming substrate. The capillary wick maydefine the internal surface surrounding the open-ended passage. Acapillary material is a material that actively conveys liquid from oneend of the material to another. The capillary material may be orientedin the storage portion to convey liquid aerosol-forming substrate to theopen-ended passage. The capillary material may have a fibrous structure.The capillary material may have a spongy structure. The capillarymaterial may comprise a bundle of capillaries. The capillary materialmay comprise a plurality of fibres. The capillary material may comprisea plurality of threads. The capillary material may comprise fine boretubes. The capillary material may comprise a combination of fibres,threads and fine-bore tubes. The fibres, threads and fine-bore tubes maybe generally aligned to convey liquid to the electric heater. Thecapillary material may comprise sponge-like material. The capillarymaterial may comprise foam-like material. The structure of the capillarymaterial may form a plurality of small bores or tubes, through which theliquid can be transported by capillary action.

The capillary material may comprise any suitable material or combinationof materials. Examples of suitable materials are a sponge or foammaterial, ceramic- or graphite-based materials in the form of fibres orsintered powders, foamed metal or plastics materials, a fibrousmaterial, for example made of spun or extruded fibres, such as celluloseacetate, polyester, or bonded polyolefin, polyethylene, terylene orpolypropylene fibres, nylon fibres or ceramic. The capillary materialmay be made of a polymeric compound, including medical grade polymerssuch as ALTUGLAS® Medical Resins Polymethlymethacrylate (PMMA), ChevronPhillips K-Resin® Styrene-butadiene copolymer (SBC), Arkema specialperformance polymers Pebax®, Rilsan®, and Rilsan® Clear, DOW (Health+™)Low-Density Polyethylene (LDPE), DOWTM LDPE 91003, DOWTM LDPE 91020 (MFI2.0; density 923), ExxonMobil™ Polypropylene (PP) PP1013H1, PP1014H1 andPP9074MED, Trinseo CALIBRE™ Polycarbonate (PC) 2060-SERIES. Thecapillary material may be made of a metallic alloy, for examplealuminium or stainless steel medical grade alloys. The capillarymaterial may have any suitable capillarity and porosity so as to be usedwith different liquid physical properties. The liquid aerosol-formingsubstrate has physical properties, including but not limited toviscosity, surface tension, density, thermal conductivity, boiling pointand atom pressure, which allow the liquid to be transported through thecapillary material by capillary action. The capillary material may beconfigured to convey the aerosol-forming substrate to the atomiser.

In at least one example embodiment, the aerosol-forming substrate may bean aerosol-forming liquid. In such example embodiments, the storageportion is a liquid storage portion for storing the aerosol-formingliquid.

The liquid aerosol-forming substrate may comprise nicotine. The nicotinecontaining liquid aerosol-forming substrate may be a nicotine saltmatrix. The liquid aerosol-forming substrate may comprise plant-basedmaterial. The liquid aerosol-forming substrate may comprise tobacco. Theliquid aerosol-forming substrate may comprise a tobacco-containingmaterial containing volatile tobacco flavour compounds, which arereleased from the aerosol-forming substrate upon heating. The liquidaerosol-forming substrate may comprise homogenised tobacco material. Theliquid aerosol-forming substrate may comprise a non-tobacco-containingmaterial. The liquid aerosol-forming substrate may comprise homogenisedplant-based material.

The liquid aerosol-forming substrate may comprise at least oneaerosol-former. An aerosol-former is any suitable known compound ormixture of compounds that facilitates formation of a dense and stableaerosol and that is substantially resistant to thermal degradation atthe temperature of operation of the system. Suitable aerosol-formers arewell known in the art and include, but are not limited to: polyhydricalcohols, such as triethylene glycol, 1,3-butanediol and glycerine;esters of polyhydric alcohols, such as glycerol mono-, di- ortriacetate; and aliphatic esters of mono-, di- or polycarboxylic acids,such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Aerosolformers may be polyhydric alcohols or mixtures thereof, such astriethylene glycol, 1,3-butanediol and glycerine. The liquidaerosol-forming substrate may comprise other additives and ingredients,such as flavourants.

The aerosol-forming substrate may comprise nicotine and at least oneaerosol former. The aerosol former may be glycerine. The aerosol-formermay be propylene glycol. The aerosol former may comprise both glycerineand propylene glycol. The aerosol-forming substrate may have a nicotineconcentration ranging from about 2% to about 10% by weight based on theweight of the aerosol-forming substrate.

Although reference is made to liquid aerosol-forming substrates above,other forms of aerosol-forming substrate may be used with other exampleembodiments. In at least one example embodiment, the aerosol-formingsubstrate may be a solid aerosol-forming substrate. The aerosol-formingsubstrate may comprise both solid and liquid components. Theaerosol-forming substrate may comprise a tobacco-containing materialcontaining volatile tobacco flavour compounds which are released fromthe substrate upon heating. The aerosol-forming substrate may comprise anon-tobacco material. The aerosol-forming substrate may further comprisean aerosol former. Examples of suitable aerosol formers are glycerineand propylene glycol.

If the aerosol-forming substrate is a solid aerosol-forming substrate,the solid aerosol-forming substrate may comprise, for example, one ormore of: powder, granules, pellets, shreds, spaghettis, strips or sheetscontaining one or more of: herb leaf, tobacco leaf, fragments of tobaccoribs, reconstituted tobacco, homogenised tobacco, extruded tobacco, castleaf tobacco and expanded tobacco. The solid aerosol-forming substratemay be in loose form, or may be provided in a suitable container orcartridge. In at least one example embodiment, the solid aerosol-formingsubstrate may contain additional tobacco or non-tobacco volatile flavourcompounds, to be released upon heating of the substrate. The solidaerosol-forming substrate may also contain capsules that, for example,include the additional tobacco or non-tobacco volatile flavour compoundsand such capsules may melt during heating of the solid aerosol-formingsubstrate.

As used herein, homogenised tobacco refers to material formed byagglomerating particulate tobacco. Homogenised tobacco may be in theform of a sheet. Homogenised tobacco material may have an aerosol-formercontent of greater than about 5% on a dry weight basis. Homogenisedtobacco material may alternatively have an aerosol former contentranging from about 5% to about 30% by weight on a dry weight basis.Sheets of homogenised tobacco material may be formed by agglomeratingparticulate tobacco obtained by grinding or otherwise comminuting one orboth of tobacco leaf lamina and tobacco leaf stems. Alternatively, or inaddition, sheets of homogenised tobacco material may comprise one ormore of tobacco dust, tobacco fines and other particulate tobaccoby-products formed during, for example, the treating, handling andshipping of tobacco. Sheets of homogenised tobacco material may compriseone or more intrinsic binders, that is tobacco endogenous binders, oneor more extrinsic binders, that is tobacco exogenous binders, or acombination thereof to help agglomerate the particulate tobacco;alternatively, or in addition, sheets of homogenised tobacco materialmay comprise other additives including, but not limited to, tobacco andnon-tobacco fibres, aerosol-formers, humectants, plasticisers,flavourants, fillers, aqueous and non-aqueous solvents and combinationsthereof.

In at least one example embodiment, the solid aerosol-forming substratemay be provided on or embedded in a thermally stable carrier. Thecarrier may take the form of powder, granules, pellets, shreds,spaghettis, strips or sheets. In at least one example embodiment, thecarrier may be a tubular carrier having a thin layer of the solidsubstrate deposited on its inner surface, or on its outer surface, or onboth its inner and outer surfaces. Such a tubular carrier may be formedof, for example, a paper, or paper like material, a non-woven carbonfibre mat, a low mass open mesh metallic screen, or a perforatedmetallic foil or any other thermally stable polymer matrix.

The solid aerosol-forming substrate may be deposited on the surface ofthe carrier in the form of, for example, a sheet, foam, gel or slurry.The solid aerosol-forming substrate may be deposited on the entiresurface of the carrier, or alternatively, may be deposited in a patternin order to provide a non-uniform flavour delivery during use.

Also provided is a kit for an electrically heated aerosol-generatingsystem, the kit comprising an electrically heated aerosol generatingdevice according to any of the embodiments described above, and aplurality of consumable cartridges according to any of the embodimentsdescribed above.

As used herein, the terms ‘upstream’ and ‘downstream’ are used todescribe the relative positions of components, or portions ofcomponents, of cartridges, aerosol-generating devices andaerosol-generating systems in relation to the direction of air drawnthrough the cartridges, aerosol-generating devices andaerosol-generating systems during use thereof. The terms ‘distal’ and‘proximal’, are used to describe the relative positions of components ofaerosol-generating devices and aerosol-generating systems in relation totheir connection to the device, such that the proximal end of acomponent is at the ‘fixed’ end which is connected to the device, andthe distal end is at the ‘free’ end, opposite to the proximal end. Wherea component is connected to the device at the downstream end of thecomponent, the downstream end may be considered as the ‘proximal’ end,and vice versa.

As used herein, the terms “longitudinal” and “length” refer to thedirection between the opposed ends of the cartridge, the device, or acomponent of the device, such as between its downstream or proximal endand the opposed upstream or distal end. The term “transverse” is used todescribe the direction perpendicular to the longitudinal direction.

The upstream and downstream ends of the cartridge and theaerosol-generating device are defined with respect to the airflow when adraw on the mouth end of the aerosol-generating device occurs. Air isdrawn into the cartridge or the device at its upstream end, passesdownstream through the cartridge or the device and exits the cartridgeor device at its downstream end.

As used herein, the term “air inlet” is used to describe one or moreapertures through which air may be drawn into the aerosol-generatingsystem.

As used herein, the term “air outlet” is used to describe one or moreaperture through which air may be drawn out of the aerosol-generatingsystem.

Features described in relation to one or more example embodiments mayequally be applied to other example embodiment. In particular, featuresdescribed in relation to the aerosol-generating device of the oneexample embodiment may be equally applied to the aerosol-generatingsystem of other example embodiments, and vice versa.

FIG. 1 is a schematic illustration of an aerosol-generating system 10according to at least one example embodiment comprising anaerosol-generating device 100 and an aerosol-generating article in theform of a consumable cartridge 200.

The device 100 comprises a main housing 102 containing a battery 104 andcontrol electronics 106. The main housing 102 also defines a cavity 108into which the cartridge 200 is received. The device 100 furtherincludes a closure body in the form of a mouthpiece portion 110including an outlet 112. In this example embodiment, the mouthpieceportion 110 is connected to the main housing 102 by a screw fitting, butany suitable kind of connection may be used, such as a hinged connectionor a snap fitting. The device 100 further includes a heater assembly 300comprising an elongate piercing assembly 302 and a plurality of electricheaters 400 supported by the piercing assembly 302. The elongatepiercing assembly 302 is positioned centrally within the cavity 108 ofthe device 100 and extends along the longitudinal axis of the cavity108. The piercing assembly 302 comprises a first hollow shaft portion304 connected to the main housing 102 and a second hollow shaft portion324 connected to the mouthpiece portion 110 via mouthpiece connectors311. The first and second hollow shaft portions 304, 324 extend alongthe same longitudinal axis and meet at a junction 330 such that theelongate piercing assembly extends along the entire length of the cavity108. The first and second hollow shaft portions 304, 324 together definean internal airflow passage 306 extending along the elongate piercingassembly 302. Air inlets 114 are provided in the main housing 102upstream of the heater assembly 300 and are in fluid communication withthe outlet 112 via the airflow passage 306.

As best seen in FIG. 2, the cartridge 200 comprises a storage portion202 including a tubular capillary wick 204 surrounded by a tubularcapillary material 206 containing liquid aerosol-forming substrate. Thecartridge 200 has a hollow cylindrical shape through which extends aninternal passageway 208. The capillary wick 204 surrounds the internalpassageway 208 so that the internal passageway 208 is at least partlydefined by an inner surface of the capillary wick 204. The upstream anddownstream ends of the cartridge 200 are capped by frangible seals 210,212. The cartridge 200 further includes a sealing ring 214, 216 at eachof the upstream and downstream ends of the internal passageway 208.

As shown in FIGS. 3A, 3B and 3C, the first hollow shaft portion 304 hasa piercing surface 308 at its distal, or downstream end and the secondhollow shaft portion 324 has a piercing surface 328 at its distal, orupstream end. In this example embodiment, the piercing surfaces 308 areeach formed by a sharp tip at the distal end of the first and secondhollow shaft portions 304, 324. The distal end of the first hollow shaftportion 304 has an inwardly tapering outer surface 309 and the distalend of the second hollow shaft portion 324 has an outwardly taperinginner surface 329, the outer and inner surfaces 309 and 329 beingco-operatively shaped such that the outer surface 309 of the firsthollow shaft portion 304 fits within the inner surface 329 of the secondhollow shaft portion 324 to form a seal around the junction 330.

In at least one example embodiment, the heater assembly 300 includesthree electric heaters 400 fixed to and spaced along the length of theelongate piercing assembly. One of the electric heaters 400 is fixed tothe first hollow shaft portion 304 while the remaining two electricheaters 400 are fixed to the second hollow shaft portion 324. It will beappreciated the heater assembly may comprise any suitable number ofelectric heaters. In at least one example embodiment, the heaterassembly may comprise a single electric heater, or two, three, four,five, six, seven, or eight or more electric heaters fixed to and spacedapart along the length of the elongate piercing member. Where the heaterassembly comprises a plurality of electric heaters, these may be dividedequally or unequally between the first and second hollow shaft portions.

Each of the electric heaters 400 is held within a plurality of apertures310 in the first and second hollow shaft portions 305, 324. Theapertures 310 are provided in pairs, with each pair supporting a singleelectric heater 400 at both of its ends. The two apertures in each pairare spaced apart around the circumferences of the hollow shaft portions304, 324 so that each of the electric heaters 400 extends across theairflow passage 306. In at least one example embodiment, the pluralityof apertures 310 comprises three pairs of apertures 312, 314, 316supporting three electric heaters 400. The three pairs of apertures 312,314, 316 are spaced apart along the length of the elongate piercingassembly 302 and aligned around the circumferences of the hollow shaftportions 304, 324 such that the longitudinal axes of the three electricheaters 400 are parallel and rotationally aligned. It will beappreciated that other arrangements of heater assembly are envisaged. Inat least one example embodiment, three alternative arrangements ofheater assembly are discussed below in relation to FIGS. 6A to 6C, FIGS.7A and 7B and FIG. 8.

The first and second hollow shaft portions 304, 324 are bothelectrically conductive and at least partially divided into a pluralityof electrically isolated sections 318, each associated with one or moreelectric heaters 400 and each electrically connected to the battery inthe device. In the case of the first hollow shaft portion 304, theelectrically isolated sections 318 are connected to the battery byelectrical connections (not shown) at the base of the first hollow shaftportion 304. In the case of the second hollow shaft portion 324,electrically isolated sections 318 may be electrically connected to thebattery in the device via the first hollow shaft portion 304 and thejunction 330, or via the mouthpiece connectors between the second hollowshaft portion 324 and the mouthpiece portion 110 and via electricalconnections (not shown) between the mouthpiece portion 110 and the mainhousing 102.

The apertures 310 are each formed in one of the electrically isolatedsections 318. The electrically isolated sections 318 are electricallyisolated from each other by insulating gaps 320. Thus, the electricheaters 400 may be electrically isolated from the each other to allowseparate operation, control, or monitoring, without the need forseparate electrical wiring for each heater. In this example, the gaps320 are air gaps. That is, the gaps 320 do not contain insulatingmaterial. In other examples, one or more of the gaps 320 may be filledor partially filled with an electrically insulating material.

As best seen in FIGS. 4A to 4C, each electric heater 400 comprises acapillary body 402, a heating element 404 arranged on an outer surfaceof the capillary body 402, and a pair of spaced apart electricalcontacts 406 fixed around the capillary body 402 and over the heatingelement 404. The capillary body 402, or capillary wick, comprises aplurality of fibres 408 through which an aerosol-forming liquid can betransported by capillary action. In this example, the plurality offibres 408 are generally aligned along the length of the capillary body402. In other example embodiments, the plurality of fibres may be wovenor braided in a specific pattern. This allows the physicalcharacteristics of the capillary wick, such as mechanical strength orcapillarity, to be altered by using a particular pattern of fibres. Itmay also allow the capillary wick to maintain its shape and dimensionsmore effectively than with parallel fibres. The capillary body iscompressible, for example due to the presence of interstices betweenadjacent fibres. In this example embodiment, the ends of the capillarybody 402 are rounded or domed. This may help to increase the surfacearea between the capillary body 402 and an aerosol-forming liquid in thecartridge 200. In other example embodiments, the ends of the capillarybody 402 may be flat or planar.

The heating element 404 of each electric heater 400 is formed from acoil of electrically resistive wire wound around the capillary body 402and extending along its entire length. The wire may have any suitablecross-sectional shape. In at least one example embodiment, the wire hasa round cross-sectional shape. In at least one example embodiment, thewire may have an oval, triangular, square, rectangular, or flatcross-sectional shape. This may increase heat transfer between thefibres 408 of the capillary body 402 and the heating element 404.

The electrical contacts 406 of each electric heater 400 comprise a firstmetallic ring 412 at a first end of the capillary body 402 and a secondmetallic ring 414 at a second end of the capillary body 402. The firstand second rings 412, 414 extend around the entire circumference of thecapillary body 402 and over the heating element 404. The inner diameterof each of the rings 412, 414 is less than the outer diameter of thecapillary body 402. Consequently, there is an interference fit betweenthe rings 412, 414 and the capillary body 402 underneath. This ensuresthat the rings 412, 414 press into the capillary body 402 and aresecured thereto, with the heating element 404 retained between. Thishelps to ensure a reliable electrical connection between the electricalcontacts 406 and the heating element 404. As the electrical contacts 406extend around the entire circumference of the capillary body 402, it isnot necessary to carefully match the rotational position of theelectrical contacts with the position of the heating coil 404 duringassembly to ensure an electrical connection.

The first and second rings 412, 414 of the electrical contacts 406 arerigid and formed from a bent sheet of metal. The opposed ends of thebent sheet are connected together at a joint 416. In this example, theopposed ends are co-operatively shaped such that the joint 416 extendsalong an oblique line. This helps each of the electrical contacts 406 tomaintain its shape by resisting relative movement between its opposedends in the length direction of the electric heater 400. In at least oneexample embodiment, the opposed ends may be co-operatively shaped sothat joint has a non-linear shape, such as a wavy, sinusoidal,parabolic, U-, V-, curved, or zig-zag shape. Again, this helps each ofthe electrical contacts 406 to maintain its shape for the reasonsdiscussed above.

In the example embodiment shown in FIGS. 4A to 4C, the capillary body402 has a circular cross-section and the electrical contacts 406 are inthe form of circular rings. However, in other example embodiments, thecapillary body 402 and electrical contacts 406 may have any suitablecross-sectional shape. In at least one example embodiment, the capillarybody and electrical contacts may have an oval, triangular, square,rectangular, or lozenge-shaped cross-sectional shape.

The electrical contacts 406 and the apertures 310 in the elongatepiercing assembly 302 are co-operatively sized to provide a frictionalfit. This ensures a secure fit between the hollow shaft portion 304 andthe electric heaters 400. This may also enable a good electricalconnection to be maintained between the heating element of each electricheater and the battery 104 in the device 100. In at least one exampleembodiment, the apertures 310 are circular to match the shape of theelectrical contacts of the electric heaters 400. In other examples, thecross-sectional shape of the electrical contacts may be different andthe shape of the apertures determined accordingly. In at least oneexample embodiment, the electrical contacts may have one or moreoutwardly extending tabs and the first and second hollow shaft portionsmay have corresponding notches around the apertures which form portsinto which the tabs may be received. Alternatively, or in addition, theelongate piercing assembly 302 may include one or more clips in whichthe tabs may be located and retained.

Referring to FIGS. 5A, 5B and 5C, insertion of the cartridge 200 intothe device 100 of the system 10 will now be described.

To insert the cartridge 200 into the device 100, and thereby assemblethe system 10, the first step is to remove the mouthpiece portion 110from the main housing 102 of the device 100 and to insert the article200 into the cavity 108 of the device 100. During insertion of cartridge200 into the cavity 108, the first piercing surface 308 at the distalend of the first hollow shaft portion 304 breaks the first frangibleseal at the upstream end of the cartridge 200, as shown in FIG. 5A.

The mouthpiece portion 110 is then placed over the end of the mainhousing 102 so that the second hollow shaft portion 324 is aligned withthe internal passageway in the cartridge 200, as shown in FIG. 5B.

As the mouthpiece portion 110 is further engaged with the main housing102, the second piercing surface 328 at the distal end of the secondhollow shaft portion 324 engages with and breaks through the secondfrangible seal at the downstream end of the cartridge 200 to create ahole in the second frangible seal. The mouthpiece portion 110 is thenfully engaged with the main housing 102 to fully insert and enclose thecartridge 200 in the cavity 108, as shown in FIG. 5C.

When the cartridge 200 is fully inserted into the cavity 108, the holesin the first and second frangible seals at the upstream and downstreamends of the cartridge 200 caused by the first and second hollow shaftportions 304, 324 each have a diameter approximately equal to the outerdiameters of the hollow shaft portions 304, 324. The sealing rings atthe upstream and downstream ends of the cartridge 200 form a seal aroundthe hollow shaft portions 304, 324. Together with the frangible sealsthis reduces or prevents leakage of liquid aerosol-forming substratefrom the cartridge 200 and out of the system 10.

As also shown in FIG. 5C, when the cartridge 200 is fully inserted intothe cavity 108 of the aerosol-generating device 100, an airflow pathway,shown by arrows in FIG. 5C, is formed through the aerosol-generatingsystem 10 via the internal passageway 208 in the cartridge 200 and theairflow passage 306 in the heater assembly 1300. As further shown inFIG. 5C, when the cartridge 200 is fully inserted, the electric heaters400 are in fluid communication with the storage portion 202 of thecartridge 200 via the capillary wick 204 at the inner surface of theinternal passageway 208 of the cartridge 200 and via the apertures inthe first and second hollow shaft portions 304, 324.

In at least one example embodiment, during vaping, liquidaerosol-forming substrate is transferred from the storage portion 202 tothe capillary body 402 of each electric heater 400 via capillary actionand through the plurality of apertures in the first and second hollowshaft portions 304, 324. In at least one example embodiment, the outerdiameter of the first and second hollow shaft portions 304, 324 of theelongate piercing assembly 302 is greater than the inner diameter of theinternal passageway 208 of the cartridge 200 so that the storage portion202 of the cartridge 200 is compressed by the heater assembly 300. Thisensures direct contact between the ends of the electric heaters 400 andthe storage portion 202 to help transfer of liquid aerosol-formingsubstrate to the electric heaters 400.

The battery supplies electrical energy to the heating element of eachelectric heater 400, via the first and second hollow shaft portions 304,324 and the electrical contacts 406. The heating elements heat up tovaporise liquid substrate in the capillary body of the electric heaters400 to create a supersaturated vapour. At the same time, the liquidbeing vaporised is replaced by further liquid moving along the capillarywick of the liquid storage portion 202 and the capillary body of eachelectric heater 400 by capillary action. (This is sometimes referred toas “pumping action”.) When draw is taken on the mouthpiece portion 110,air is drawn through the air inlets 114, through the airflow passage ofthe hollow shaft portion 304, past the electric heaters 400, into themouthpiece portion 110 and out of the outlet 112. The vaporisedaerosol-forming substrate is entrained in the air flowing through theairflow passage of the hollow shaft portion 304 and condenses within themouthpiece portion 110 to form an inhalable aerosol, which is carriedtowards the outlet 112.

The device may be operated by a manually operated switch (not shown) onthe device 100. Alternatively, or in addition, the device may include asensor for detecting a puff or draw. When a puff is detected by thesensor, the control electrics control the supply of electrical energyfrom the battery to the electric heaters 400. The sensor may compriseone or more separate components. In some example embodiments, the puffsensing function is performed by the heating elements of the heater andwick assemblies. In at least one example embodiment, by measuring withthe control electronics one or more electrical parameters of the heatingelements and detecting a particular change in the measured electricalparameters which is indicative of a puff.

During operation of the system, the distribution of liquidaerosol-forming substrate in the cartridge may change. In at least oneexample embodiment, as the liquid aerosol-forming substrate in thestorage portion is depleted, or where the system is held at an angle fora sufficient period of time. This change in the distribution of liquidaerosol-forming substrate may lead to differences in the amount ofliquid in the capillary body of each electric heater and, consequently,the temperature of the heating element of each electric heater. This isdiscussed below in relation to FIG. 6.

FIG. 5D shows a longitudinal cross-section of the cartridge 200 andheater assembly 300 of the aerosol-generating system following a periodin which the system has been held in a tilted position. As shown, theremaining liquid 203 in the cartridge 200 has settled in the storageportion 202 at an angle to the heater assembly 300. As the electricheaters are spaced apart along the length of the cartridge 200, theamount of liquid aerosol-forming substrate drawn up by the capillarybodies of the electric heaters is not uniform. In at least one exampleembodiment, the capillary body 402 of the first electric heater 401 atthe upstream end of the heater assembly 300 is saturated with liquidaerosol-forming substrate, while the second electric heater 403 midwayalong the length of the heater assembly 300 is only partially wet withliquid aerosol-forming substrate, and the third electric heater 405 atthe downstream end of the heater assembly 300 is dry. In at least oneexample embodiment, the electric heaters 401, 403, 405 run at differenttemperatures. As the electrical parameters of each electric heater, suchas the resistivity, conductivity, impedance, capacitance, current,voltage, and resistance of the heating element, may vary as a functionof the temperature, the distribution of the liquid aerosol-formingsubstrate or the remaining amount of liquid aerosol-forming substratemay be estimated by the control circuitry through measuring theelectrical parameters of each electric heater. The control electronicsis configured to separately measure one or more electrical parameters ofeach electric heater during use and to calculate an estimated remainingamount, or estimated distribution, of liquid aerosol-forming substratein the cartridge based on differences in the measured electricalparameters from the electric heaters. Thus, the electric heatersfunction both as heaters and as sensors.

The device includes an indicator (not shown), such as a display or audioor haptic output, connected to the control circuitry, which may be usedto convey information regarding the estimated remaining amount of liquidaerosol-forming substrate in the cartridge 200. When the estimatedremaining amount falls below a threshold level, the electric circuitrymay also be configured to operate the indicator to alert the adult vaporand to indicate that the cartridge needs changing. The control circuitrymay also be configured to estimated the distribution of liquidaerosol-forming substrate in the cartridge based on differences in themeasured electrical parameters from the electric heaters and to operatethe indicator when the estimated distribution suggests that system hasbeen held at a particular angle for too long to alert that theorientation of the device 100 should be altered, at least temporarily,to allow the liquid aerosol-forming substrate to be redistributed in thestorage portion. In this, or other example embodiments, the controlcircuitry may be configured to alert an adult vapor about the estimatedremaining amount or estimated distribution via a communication link witha separate device, such as a smartphone, swart-watch, tablet, desktopcomputer, or similar device.

In addition to detecting differences in electrical parameters in theelectric heaters 400 and calculated an estimated remaining amount, orestimated distribution, of liquid aerosol-forming substrate in thecartridge 200, the control circuitry 106 is also configured to controlthe supply of electrical power to each of the electric heaters 400 inresponse to the estimated remaining amount, or estimated distribution.In at least one example embodiment, where the measured electricalparameters indicate that one or more of the electric heaters 400 ispartially dry, the control electronics 106 is configured to reduce thesupply of electrical energy to that electric heater. This allows thesystem 10 to determine which of the electric heaters 400 is in the bestcondition to generate aerosol in the most effective way. This allowsadverse changes to the properties of aerosol generated by the system 10,caused by variations in wetness and temperature across the electricheaters, to be substantially minimised and/or reduced. It may alsoreduce energy consumption of the system 10, and reduce the risk ofdamage to the electric heaters due to over heating. Where the electricalparameters indicate that one or more of the electric heaters 400 is dry,the control electronics 106 is configured to reduce the supply ofelectrical energy to that electric heater to zero.

FIGS. 6A, 6B and 6C illustrate a heater assembly 600 according to atleast one example embodiment. The heater assembly 600 has a similarstructure to the heater assembly 300 of example embodiments describedabove and where the same features are present, like reference numeralshave been used. As with the heater assembly of the first embodiment, theelongate piercing member 602 formed by the first and second hollow shaftportions 604, 624 comprises three pairs of apertures 612, 614, 616 inwhich three electric heaters 401, 403, 405 are held such that theirlongitudinal axes are parallel in the transverse direction. However,unlike in the heater assembly 300 of the first embodiment, in the heaterassembly 600 according to a second embodiment, the central, second pairof apertures 614 is offset around the circumference of the first hollowshaft portion 604 by 90 degrees relative to the first and third pairs ofapertures 612, 616. Consequently, the longitudinal axis of the centralelectric heater 403 is rotated by 90 degrees about the longitudinal axisof the hollow shaft portions 604, 624 relative to the first and secondelectric heaters 401, 405. This may allow for more efficient use of theliquid aerosol-forming substrate in the cartridge in comparison to theheater assembly 300 of the first embodiment.

FIGS. 7A and 7B illustrate a heater assembly 700 according to at leastone example embodiment. The heater assembly 700 has a similar structureto the example embodiments of heater assembly 300 and 600 and where thesame features are present, like reference numerals have been used. Aswith the heater assembly 600, the hollow shaft portion 704 comprisesthree pairs of apertures 712, 714, 716 in which three electric heaters401, 403, 405 are held such that their longitudinal axes are parallel inthe transverse directions. However, unlike in the heater assembly 600,in the heater assembly 700, the pairs of apertures 712, 714, 716 areeach offset around the circumference of the first and second hollowshaft portions 704, 724 so that the longitudinal axes of the electricheaters 401, 403, 405 are parallel in the transverse direction butrotated about the longitudinal axis of the hollow shaft portions 704,724 relative to each other. The longitudinal axis of each electricheater 401, 403, 405 is rotated by a uniform amount of less than about90 degrees from its adjacent electric heater or heaters. Consequently,the electric heaters 401, 403, 405 are arranged in a spiral, or helix,pattern along the elongate piercing member 702. In at least one exampleembodiment, the electric heaters may be rotated about the longitudinalaxis of the hollow shaft portions 704, 724 by a non-uniform amount.

FIG. 8 illustrates a heater assembly 800 according to at least oneexample embodiment. As with the heater assemblies 300, 600 and 700 ofother example embodiments described herein, the heater assembly 800comprises an elongate piercing assembly 802 comprising first and secondelectrically conductive hollow shaft portions 804, 824 defining anairflow passage. Again, the first and second hollow shaft portions 804,824 comprise a plurality of apertures 810 spaced apart along the lengthof the elongate piercing assembly 802 and are at least partially dividedinto a plurality of electrically isolated sections 818 which areseparated from each other by insulating gaps 820. The apertures 810 ofthe heater assembly 800 are not arranged to support separate electricheaters. Instead, the apertures 810 are arranged in a plurality ofgroups of apertures 810 spaced apart along the length of the elongatepiercing assembly 802, with each group of apertures 810 defining anelectric heater 850 comprising one or more heating elements formed bynarrow regions of the hollow shaft portion 804, 824 located betweenadjacent apertures 810. In this manner, the electric heaters 850 aredefined by the hollow shaft portions 804, 824 themselves. The groups ofapertures 810, and thus the electric heaters 850, are each formed suchthat they extend between two of the electrically isolated sections 818.In the example shown in FIG. 8, the electric heaters 850 are eachlocated at the end of a different electrically isolated section 818. Inthis manner, the electric heaters 850 are electrically isolated fromeach other by the insulating gaps 820. The apertures 810 are sized sothat, when in use, liquid aerosol-forming substrate is drawn in to theelectric heaters 850 by capillary action through the apertures 810. Inat least one example embodiment, as shown in FIG. 8, the groups ofapertures 810 are aligned around the circumference of the hollow shaftportions 804, 824. In other example embodiments, two or more of thegroups of apertures 810 may be offset around the circumferences of thehollow shaft portions 804, 824.

The example embodiments described above illustrate but do not limit theinvention. It is to be understood that other example embodiments may bemade and the example embodiments described herein are not exhaustive.

We claim:
 1. An electrically heated aerosol-generating systemcomprising: a cartridge including, a storage portion containing anaerosol-forming substrate, and an open ended passage extending throughthe cartridge; and an aerosol-generating device including, a mainhousing defining a cavity configured to receive at least a portion ofthe cartridge, a closure engageable with the main housing, a heaterassembly at least partially in the main housing, the heater assemblyincluding, an elongate piercing assembly configured to extend into theopen ended passage of the cartridge, the elongate piercing assemblyincluding, a first hollow shaft portion connected to the main housing, asecond hollow shaft portion connected to the closure, the first hollowshaft portion and the second hollow shaft portion extending along a samelongitudinal axis, and the first hollow shaft portion and the secondhollow shaft portion being configured to meet at a junction such thatthe elongate piercing assembly extends along an entire length of thecavity, and at least one electric heater fixed to the elongate piercingassembly and configured to heat the aerosol forming substrate.
 2. Theelectrically heated aerosol-generating system of claim 1, wherein theclosure comprises: a mouthpiece including at least one outlet.
 3. Theelectrically heated aerosol-generating system of claim 1, wherein thefirst hollow shaft portion comprises: a first piercing surface at adistal end thereof, the first piercing surface configured to breakthrough a first frangible seal across a first end of the open endedpassage when the cartridge is inserted into the cavity.
 4. Theelectrically heated aerosol-generating system of claim 3, wherein thesecond hollow shaft portion comprises: a second piercing surface at adistal end thereof, the second piercing surface configured to breakthrough a second frangible seal across a second end of the open endedpassage when the closure body is engaged with the main housing,
 5. Theelectrically heated aerosol-generating system of claim 4, wherein thedistal end of the first hollow shaft portion and the distal end of thesecond hollow shaft portion are each co-operatively shaped such that aseal is formed around the junction.
 6. The electrically heatedaerosol-generating system of claim 5, wherein the distal end of one ofthe first hollow shaft portion and the second hollow shaft portion hasan inwardly tapering outer surface and the distal end of the other oneof the first and second hollow shaft portions has an outwardly taperinginner surface.
 7. The electrically heated aerosol-generating devicesystem of claim 1, wherein the first hollow shaft portion and the secondhollow shaft portion are electrically conductive and configured toconnect the one or more electric heaters to an electrical power supply.8. The electrically heated aerosol-generating device system of claim 1,wherein the heater assembly further comprises: a plurality of electricheaters, the plurality of heaters being fixed to and spaced along alength of the elongate piercing assembly.
 9. The electrically heatedaerosol-generating device system of claim 8, wherein the plurality ofelectric heaters comprises: one or more electric heaters fixed to thefirst hollow shaft portion; and one or more electric heaters fixed tothe second hollow shaft portion.
 10. The electrically heatedaerosol-generating system of claim 8, wherein each of the plurality ofelectric heaters extend across an internal airflow passage transverse toa longitudinal direction of the elongate piercing assembly.
 11. Theelectrically heated aerosol-generating system of claim 8, wherein thefirst hollow shaft portion, the second hollow shaft portion, or both thefirst hollow shaft portion and the second hollow shaft portioncomprises: a plurality of apertures in which the plurality of electricheaters are held, the plurality of electric heaters being in fluidcommunication with the storage portion of a cartridge received in thecavity via the plurality of apertures.
 12. The electrically heatedaerosol-generating system of claim 1, wherein the closure is connectableto the main housing via a screw fitting.
 13. The electrically heatedaerosol-generating system of claim 1, wherein the cartridge furthercomprises: a capillary wick in fluid communication with theaerosol-forming substrate.
 14. The electrically heatedaerosol-generating system of claim 1, wherein the cartridge has ahollow, cylindrical shape.
 15. The electrically heatedaerosol-generating system of claim 1, wherein the cartridge furthercomprises: at least one sealing ring at an end thereof.
 16. Theelectrically heated aerosol-generating system of claim 1, wherein the atleast one electric heater comprises: a capillary body; and at least oneheating element arranged on an outer surface of the capillary body. 17.The electrically heated aerosol-generating system of claim 1, whereinthe at least one heating element comprises a coil of wire.